Xhr.IFramed form submit to another host

When a form is submitted to another host, then the Iframed request won't have an access to the iframe content, so we need to add some try/catch construction like that

  onLoad: function() {
    ...
    try {
      this.responseText = window[this.iframe.id].document.documentElement.innerHTML;
    } catch(e) {}
    ...
  }